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20
21#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
22#include <linux/module.h>
23#include <linux/skbuff.h>
24#include <linux/netfilter/x_tables.h>
25#include <linux/slab.h>
26#include <linux/leds.h>
27#include <linux/mutex.h>
28
29#include <linux/netfilter/xt_LED.h>
30
31MODULE_LICENSE("GPL");
32MODULE_AUTHOR("Adam Nielsen <a.nielsen@shikadi.net>");
33MODULE_DESCRIPTION("Xtables: trigger LED devices on packet match");
34MODULE_ALIAS("ipt_LED");
35MODULE_ALIAS("ip6t_LED");
36
37static LIST_HEAD(xt_led_triggers);
38static DEFINE_MUTEX(xt_led_mutex);
39
40
41
42
43
44
45struct xt_led_info_internal {
46 struct list_head list;
47 int refcnt;
48 char *trigger_id;
49 struct led_trigger netfilter_led_trigger;
50 struct timer_list timer;
51};
52
53#define XT_LED_BLINK_DELAY 50
54
55static unsigned int
56led_tg(struct sk_buff *skb, const struct xt_action_param *par)
57{
58 const struct xt_led_info *ledinfo = par->targinfo;
59 struct xt_led_info_internal *ledinternal = ledinfo->internal_data;
60 unsigned long led_delay = XT_LED_BLINK_DELAY;
61
62
63
64
65
66 if ((ledinfo->delay > 0) && ledinfo->always_blink &&
67 timer_pending(&ledinternal->timer))
68 led_trigger_blink_oneshot(&ledinternal->netfilter_led_trigger,
69 &led_delay, &led_delay, 1);
70 else
71 led_trigger_event(&ledinternal->netfilter_led_trigger, LED_FULL);
72
73
74 if (ledinfo->delay > 0) {
75 mod_timer(&ledinternal->timer,
76 jiffies + msecs_to_jiffies(ledinfo->delay));
77
78
79 } else if (ledinfo->delay == 0) {
80 led_trigger_event(&ledinternal->netfilter_led_trigger, LED_OFF);
81 }
82
83
84
85 return XT_CONTINUE;
86}
87
88static void led_timeout_callback(unsigned long data)
89{
90 struct xt_led_info_internal *ledinternal = (struct xt_led_info_internal *)data;
91
92 led_trigger_event(&ledinternal->netfilter_led_trigger, LED_OFF);
93}
94
95static struct xt_led_info_internal *led_trigger_lookup(const char *name)
96{
97 struct xt_led_info_internal *ledinternal;
98
99 list_for_each_entry(ledinternal, &xt_led_triggers, list) {
100 if (!strcmp(name, ledinternal->netfilter_led_trigger.name)) {
101 return ledinternal;
102 }
103 }
104 return NULL;
105}
106
107static int led_tg_check(const struct xt_tgchk_param *par)
108{
109 struct xt_led_info *ledinfo = par->targinfo;
110 struct xt_led_info_internal *ledinternal;
111 int err;
112
113 if (ledinfo->id[0] == '\0') {
114 pr_info("No 'id' parameter given.\n");
115 return -EINVAL;
116 }
117
118 mutex_lock(&xt_led_mutex);
119
120 ledinternal = led_trigger_lookup(ledinfo->id);
121 if (ledinternal) {
122 ledinternal->refcnt++;
123 goto out;
124 }
125
126 err = -ENOMEM;
127 ledinternal = kzalloc(sizeof(struct xt_led_info_internal), GFP_KERNEL);
128 if (!ledinternal)
129 goto exit_mutex_only;
130
131 ledinternal->trigger_id = kstrdup(ledinfo->id, GFP_KERNEL);
132 if (!ledinternal->trigger_id)
133 goto exit_internal_alloc;
134
135 ledinternal->refcnt = 1;
136 ledinternal->netfilter_led_trigger.name = ledinternal->trigger_id;
137
138 err = led_trigger_register(&ledinternal->netfilter_led_trigger);
139 if (err) {
140 pr_err("Trigger name is already in use.\n");
141 goto exit_alloc;
142 }
143
144
145 if (ledinfo->delay > 0)
146 setup_timer(&ledinternal->timer, led_timeout_callback,
147 (unsigned long)ledinternal);
148
149 list_add_tail(&ledinternal->list, &xt_led_triggers);
150
151out:
152 mutex_unlock(&xt_led_mutex);
153
154 ledinfo->internal_data = ledinternal;
155
156 return 0;
157
158exit_alloc:
159 kfree(ledinternal->trigger_id);
160
161exit_internal_alloc:
162 kfree(ledinternal);
163
164exit_mutex_only:
165 mutex_unlock(&xt_led_mutex);
166
167 return err;
168}
169
170static void led_tg_destroy(const struct xt_tgdtor_param *par)
171{
172 const struct xt_led_info *ledinfo = par->targinfo;
173 struct xt_led_info_internal *ledinternal = ledinfo->internal_data;
174
175 mutex_lock(&xt_led_mutex);
176
177 if (--ledinternal->refcnt) {
178 mutex_unlock(&xt_led_mutex);
179 return;
180 }
181
182 list_del(&ledinternal->list);
183
184 if (ledinfo->delay > 0)
185 del_timer_sync(&ledinternal->timer);
186
187 led_trigger_unregister(&ledinternal->netfilter_led_trigger);
188
189 mutex_unlock(&xt_led_mutex);
190
191 kfree(ledinternal->trigger_id);
192 kfree(ledinternal);
193}
194
195static struct xt_target led_tg_reg __read_mostly = {
196 .name = "LED",
197 .revision = 0,
198 .family = NFPROTO_UNSPEC,
199 .target = led_tg,
200 .targetsize = sizeof(struct xt_led_info),
201 .checkentry = led_tg_check,
202 .destroy = led_tg_destroy,
203 .me = THIS_MODULE,
204};
205
206static int __init led_tg_init(void)
207{
208 return xt_register_target(&led_tg_reg);
209}
210
211static void __exit led_tg_exit(void)
212{
213 xt_unregister_target(&led_tg_reg);
214}
215
216module_init(led_tg_init);
217module_exit(led_tg_exit);
218